4.5 FUSE SWITCHGEARS
Fuse-switches and switch-fuses shall be of totally enclosed, flush or surface mounting, double air break, quick-make and quick-break type complete with phase barriers and fully comply with IEC 60947-1 and 60947-3. They shall be of utilization category AC-23A. They shall be equipped with operating handle, position ON-OFF indicator and mechanical door interlock to prevent the cover from being opened with the switch closed and the switch being closed with the cover opened. However this interlock shall be able to be defeated by competent person for maintenance purpose. The doors shall be provided with dust seal.
They shall be equipped with replaceable HRC fuses. The fuse holder shall have shrouded base contact with provision for busbar mounting and front wiring. The fuse links and fuse carrier shall comply with relevant parts of IEC 60269. Suitable knockouts shall be provided for cable entry.